Method of designing and forming a demolition tool unit

ABSTRACT

A multiple tool attachment system is adapted to be attached to demolition equipment. The system includes a universal body attached to the demolition equipment. A series of tools is independently attachable to the universal body. The universal body includes a guide slot extending longitudinally along the universal body. Each tool generally includes a pair of pivotable jaws adapted to be pivotably attached to the universal body with at least one linkage extending from the universal body and attachable to each jaw of the tool. A slide member is received within the guide slot, with each linkage attached to the slide member, and a piston cylinder arrangement is attached to the universal body and coupled to the slide member for moving the slide member and the jaws. The multiple tool attachment system is provided with quick change features and is designed to optimize the cutting characteristics throughout the movement cycle.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a division of U.S. application Ser. No. 11/101,265filed Apr. 7, 2005, which is a division of U.S. application Ser. No.10/089,481, now U.S. Pat. No. 6,994,284, issued on Feb. 7, 2006, whichis the national phase of International Application No. PCT/US00/02836,filed Oct. 13, 2000, designating inter alia, the United States, whichclaimed the benefit of U.S. Provisional Application Nos. 60/159,869,filed Oct. 15, 1999, and 60/195,797, filed Apr. 10, 2000.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a tool attachment system forconstruction or demolition equipment which is adapted to be attached toa backhoe for attaching multiple tools, such as a heavy-duty metalcutting shear, a plate shear, a concrete crusher, a grapple or the like.More particularly, the present invention relates to a multiple toolattachment system for attaching tools having plural movable jaws.

2. Description of Related Art

The present application refers to demolition equipment; however, theequipment is also referred to as construction equipment, scrap handlingequipment and the like. The description of demolition equipment orconstruction equipment is not intended to be restrictive of theequipment being referenced. Demolition equipment, such as heavy-dutymetal cutting shears, grapples and concrete crushers, has been mountedon backhoes powered by hydraulic cylinders for a variety of jobs in thedemolition field. This equipment provides for the efficient cutting andhandling of scrap. For example, in the dismantling of an industrialbuilding, metal scrap in the form of various diameter pipes, structuralI-beams, channels, angles, sheet metal plates and the like, must beefficiently severed and handled by heavy-duty metal shears. Such shearscan also be utilized for reducing automobiles, truck frames, railroadcars and the like. The shears must be able to move and cut the metalscrap pieces regardless of the size or shape of the individual scrappieces and without any significant damage to the shears. In thedemolition of an industrial building, concrete crushing devices, such asa concrete pulverizer or concrete crackers, are also used to reduce thestructure to manageable components which can be easily handled andremoved from the site. Wood shears and plate shears also representspecialized cutting devices useful in particular demolition or debrisremoval situations depending on the type of scrap. Also, a grapple isoften utilized where handling of debris or work pieces is a primaryfunction of the equipment. Historically, all of these pieces ofequipment represent distinct tools having significant independentcapital cost. Consequently, the demolition industry has tended todevelop one type of tool that can have the greatest possible utility andapplication.

With regard to metal shears, one type of known shear is a shear having afixed blade and a movable blade pivoted thereto. The movable blade ispivoted by hydraulic cylinder to provide a shearing action between theblades for severing the work pieces. Examples of this type of shear canbe found in my prior U.S. Pat. Nos. 4,403,431; 4,670,983; 4,897,921;5,926,958; and 5,940,971 which are incorporated herein by reference.

The prior art has also developed a variety of demolition tools utilizinga plurality of movable jaws. U.S. Reissue Pat. No. 35,432 and U.S. Pat.No. 5,060,378 both disclose heavy-duty metal cutting shears having abody and a pair of movable jaws mounted to the frame for pivoting abouta common point. Each jaw includes a plurality of cutting inserts inshearing relation with the inserts on the other jaw, with one jawforming a slot for maintaining the inserts in shearing relation to eachother throughout the cutting movement. Each jaw is operated by anindependent hydraulic cylinder. The jaw configuration provides ahook-shaped structure with one of the jaws having a cutting or piercingtip at the end thereof. However, these patents do not optimize the jawstructure for the purpose of cutting. Additionally, the independentcylinders increase the cost and prevent a compact shear design.

U.S. Pat. No. 5,359,775 discloses a metal cutting shear with a pair ofmovable jaws pivotally mounted to a frame with a pair of jaws operatedoff of a common piston extending between the jaws.

U.S. Pat. Nos. 4,838,493; 4,890,798; 5,044,569; 5,636,802; and 5,738,289all disclose a variety of concrete crushers having a plurality ofmovable jaws operated through hydraulic cylinders. U.S. Pat. Nos.4,903,408; 5,044,568; 5,199,658; 5,243,761; and 5,626,301 also disclosea variety of demolition equipment having a plurality of movable jaws.

The prior art does not provide a system for easily changing tools or asystem which allows complete separate tools to efficiently share acommon structure. Further, the prior art fails to optimize the jawstructure utilized in the individual tools, such as metal cuttingshears, to maximize power and efficiency. Additionally, the prior artprovides a complex arrangement for rotations of the tool and jawswithout sufficient protection for any hydraulic cylinder powering theworking jaws.

SUMMARY OF THE INVENTION

The object of the present invention is to overcome the aforementioneddrawbacks of the prior art. It is a further object of the presentinvention to provide a multiple tool attachment system which is easilyconverted between a plurality of distinct tools. A further object of thepresent invention is to provide a demolition tool having a plurality ofmovable jaws which optimizes the jaw structure. A further object of thepresent invention is to provide a demolition tool which optimizes theratio between the jaw and the jaw power structure to provide optimumpower performance throughout the blade movement cycle. A further objectof the present invention is to provide a demolition tool system thatsimplifies the construction of the tool system, including rotatingtools. A further object of the present invention is to provide a methodfor designing a demolition tool and tool system.

The objects of the present invention are achieved by a multiple toolattachment system according to the present invention. The attachmentsystem is adapted to be attached to demolition equipment, also referredto as construction equipment, scrap handling equipment and the like. Thesystem includes a universal body attachable the demolition equipment, ahydraulic cylinder attached to the universal body, a pair of linkagesadapted to be coupled with the hydraulic cylinder, and a plurality ofdemolition tool units each selectively, removably attachable to the bodyand the hydraulic cylinder.

Each tool unit includes a pair of pivotable blades or jaws adapted to bepivotally connected to the body and to the pair of linkages. In oneembodiment, the tool unit includes a pair of movable blades pivotedtogether with a common pivot pin connecting the blades together, and abridge housing coupled to the pivot pin providing a quick release systemfor attaching the tool set to the body.

In one embodiment of the invention, the universal body includes a guideslot extending longitudinally along the body. A slide member is receivedwithin the guide slot, with each linkage attached to the slide memberand the piston cylinder arrangement attached to the body and coupled tothe slide member for moving the slide member and the blades. Thelinkages may be attached to the slide member at a common point.Additionally, the linkages may have a common sleeve adapted to hold thelinkages together when decoupled from the slide member. The universalbody may be provided with pivotable sides and/or with side access panelsto assist in repair, maintenance and tool changing.

The demolition equipment is provided with quick change features and isdesigned to optimize the cutting characteristics throughout the movementcycle. Specifically, the lengths of the linkages and the lengths of therelevant lever arms for each blade of a tool set may be set to besubstantially equal or varied. In general, these jaw and link dimensionsmay be selected for a desired positioning of the power curve of the jawto optimize the performance throughout the intended operatingconditions. The jaw and link dimensions may be selected to shape orregulate the power curve in a desired manner. For example, the relativedimensions of the jaw sets may be selected to provide an increasingpower curve throughout the blade closing motion or, alternatively, therelative dimensions of the jaw sets may be selected to have the powercurve peak slightly before the end of the blade closing motion. In oneshear of the present invention, the jaw depth and maximum jaw openingare also the same as the lever arm and linkage lengths. Additionally,the jaw design of the shear of the present invention is designed toperform the majority of the heavy cutting at the throat of the pluralmoving jaws. The concepts of the present invention can be incorporatedinto a guided single moving blade demolition tool.

These and other advantages of the present invention will be clarified inthe description of the preferred embodiments wherein like referencenumerals represent like elements throughout.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view illustrating a heavy-duty shear according to thepresent invention incorporated into a universal body for a constructiontool system according to the present invention;

FIG. 2 is a side view of a shear similar to the shear of FIG. 1 withouta rotator in the body;

FIG. 3 is a side view of the shear in FIG. 1 with an outer side panel ofthe body removed;

FIG. 4 is a sectional view taken along line A-A of FIG. 3;

FIG. 5 is a plan view of the shear in FIG. 1;

FIG. 6 is an enlarged plan view, partially in section, of a slide memberof the universal body according to the present invention;

FIG. 7 is a side view of the slide member illustrated in FIG. 6;

FIG. 8 is a plan view, partially in section, of a main shaft assembly ofa tool unit mounted on the universal body of the construction toolsystem shown in FIG. 1;

FIGS. 9-11 a sequentially illustrate the disassembly of a tool unitmounted on the universal body of the construction tool system shown inFIG. 1;

FIG. 11 b is a front view of a modified bridge of the quick changesystem of the present invention;

FIG. 11 c is an exploded view of the quick change system used with themodified bridge of FIG. 11 b;

FIG. 11 d is a side view of a keeper pin used in the quick change systemof FIGS. 11 b-c;

FIG. 12 is a side view of a plate shear according to the presentinvention incorporated into the universal body of FIG. 1;

FIG. 13 is a front view of the plate shear illustrated in FIG. 12;

FIG. 14 is a side view of a concrete cracker according to the presentinvention incorporated into the universal body of FIG. 1;

FIG. 15 is a front view of the concrete cracker illustrated in FIG. 14;

FIG. 16 is a side view of a concrete pulverizer according to the presentinvention incorporated into the universal body of FIG. 1;

FIG. 17 is a front view of the concrete pulverizer illustrated in FIG.16;

FIG. 18 is a side view of a wood shear according to the presentinvention incorporated into the universal body of FIG. 1;

FIG. 19 is a front view of the wood shear illustrated in FIG. 18;

FIG. 20 is a side view of a grapple according to the present inventionincorporated into the universal body of FIG. 1;

FIG. 21 is a front view of the grapple illustrated in FIG. 20;

FIG. 22 is a side view of an iron and rail cracker according to thepresent invention incorporated into the universal body of FIG. 1;

FIG. 23 is a front view of the iron and rail cracker illustrated in FIG.22;

FIG. 24 is a sectional view of the universal body illustrated in FIG. 1taken along line A-A of FIG. 5;

FIG. 25 is a sectional view of a hydraulic cylinder for the universalbody of the present invention;

FIG. 26 is a side view schematically illustrating a jaw and a linkagearrangement of the shear of FIG. 1;

FIG. 27 a is a graph of the power curve and relative jaw position for ashear having the linkage arrangement according to FIG. 26;

FIG. 27 b is a graph of the power curve of a shear designed according tothe present invention to have the power curve peak near the end of thejaw motion;

FIG. 28 is a side view similar to FIG. 1 illustrating a heavy-duty shearaccording to another embodiment of the present invention;

FIG. 29 is a top view of the shear illustrated in FIG. 28;

FIG. 30 is a sectional view of the shear illustrated in FIG. 28;

FIGS. 31-34 sequentially illustrate the disassembly of a tool unitmounted on a universal body illustrated in FIG. 28;

FIG. 35 is a side view of the shear according to FIG. 28 incorporatedinto a modified universal body;

FIG. 36 is a plan view of a modified universal body according to thepresent invention;

FIG. 37 is a plan view of another modified universal body according tothe present invention;

FIG. 38 is a side view of the universal body illustrated in FIG. 37;

FIG. 39 is a side view of the shear according to FIG. 28 incorporatedinto a modified universal body;

FIG. 40 is a plan view of the universal body illustrated in FIG. 39;

FIG. 41 is a schematic side view of a shear according to the presentinvention incorporated into a further modified universal body;

FIG. 42 is a schematic side view of a jaw portion of a shear accordingto the present invention;

FIG. 43 is a side view, partially in section, of a shear according tothe present invention incorporated into a further modified universalbody;

FIG. 44 is a side view of a shear according to the present invention;

FIG. 45 is a side view, with a front side removed for clarity, of theshear illustrated in FIG. 44;

FIG. 46 is a sectional view taken along line A-A of FIG. 45;

FIG. 47 is a schematic side view of a shear according to the presentinvention;

FIG. 48 is a schematic side view of the shear illustrated in FIG. 47 inthe closed position;

FIG. 49 is a side view, partially in section, of a shear according tothe present invention incorporated into a further modified universalbody;

FIG. 50 is a rear view of a rotary coupling of the shear in FIG. 49;

FIG. 51 is an enlarged view of a connector pin assembly for the rotarycoupling in FIG. 50;

FIG. 52 is a side view of an adapter of the shear in FIG. 49;

FIG. 53 is a front view of the adapter of FIG. 52;

FIG. 54 is a side view, partially in section, of a shear similar to theshear of FIG. 49 without a rotary coupling in the body; and

FIG. 55 is a side view, partially in section, of a shear similar to theshear of FIG. 49 and formed as a stick mounted type shear.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 illustrates a multiple tool attachment according to the presentinvention adapted to be attached to demolition equipment, such as abackhoe (not shown). The multiple tool attachment is adapted to connectone of a series of tools or tool units to the demolition equipment.

FIG. 1 illustrates a shear 10 coupled to the multiple tool attachment.The shear 10 includes a first blade 12 and a second blade 14 pivotallyconnected at a hub or main pin 16 to a universal body 18. The universalbody 18 is referred to as the universal body 18 because it remainscommon to a series of tools or tool units in the attachment systemaccording to the present invention. The universal body 18 is comprisedof sides 19, a bearing housing 20 and a yoke 21. The main pin 16provides a common pivot for both the first blade 12 and second blade 14.

The bearing housing 20 includes spaced mounting apertures 22 forattaching the universal body 18 to the demolition equipment in aconventional fashion through an adaptor (not shown). The adaptor willpivotally connect the universal body 18 to the demolition equipment andto a controlling piston for pivoting of the universal body 18. Theadapter is intended to conform to the specific demolition equipment suchthat the shape of the adapter will differ depending on the specificdemolition equipment utilized.

A rotary coupling 23 is between the bearing housing 20 and the yoke 21.The rotary coupling 23 allows for a rotation of the remaining portionsof the universal body 18 relative to the bearing housing 20 and theassociated demolition equipment. Essentially, the rotary coupling 23allows for 360 degree rotation for angular orientation of the universalbody 18 and associated tool such as shear 10. A motor 25, as shown inFIG. 5, is attached to the bearing housing 20 and geared to the rotarycoupling 23 for rotationally positioning the universal body 18.

FIG. 2 illustrates a shear 10′ similar to shear 10 illustrated inFIG. 1. The shear 10′ has a modified universal body 18′ that does notinclude a rotary coupling attached to the bearing housing 20. A bearinghousing 20′ and a yoke 21′ are of a unitary construction. The universalbody 18′ is appropriate where no rotation of the tool is desired.

As best shown in FIG. 3, a first linkage 24 is pivotally connected at aremovable pivot pin 26 to the first blade 12 and a second linkage 28 ispivotally connected at a removable pivot pin 30 to the second blade 14.The first linkage 24 and second linkage 28 are pivotally connected to aslide member 32 at a common pivot pin 34. The slide member 32 isattached to a piston rod 36, as shown in FIG. 25, which is movable by adouble-acting hydraulic cylinder 38 (shown in the universal body 18 inFIG. 30). The hydraulic cylinder 38 is pivotally attached to theuniversal body 18 through a trunnion 40. The details of the hydrauliccylinder 38 are shown in FIGS. 24 and 25 and are described in detailbelow.

As shown in FIGS. 3 and 4, sides 19 of the universal body 18 include alongitudinally extending guide slot or groove 44 which receives andguides the slide member 32 as shown in FIG. 4. The pivot pin 34 forconnecting the first linkage 24 and second linkage 28 to the slidemember 32 is aligned with the piston rod 36 and hydraulic cylinder 38 asillustrated in the figures. Having the linkages 24 and 28 attached tothe slide member 32 at a common point in line with the hydrauliccylinder 38 helps maximize the power and efficiencies of the tool, suchas shear 10, while minimizing the detrimental forces acting on thehydraulic cylinder 38. Additionally, the guiding of slide member 32within the slot 44 resists torsional forces which otherwise disrupt theaction of the tool and the operation of the hydraulic cylinder 38. Thestructure of the slide member 32 is shown in detail in FIGS. 4 and 6-7and will be described in detail below.

A significant feature of the multiple tool attachment of the presentinvention is the quick change design incorporated into the connectionbetween the jaw set of a specific tool and the universal body 18. Thisconnection and the process of disassembly is shown in FIGS. 9-11 a. Abridge housing 48 surrounds the main pin 16 and is utilized for quicklyand easily attaching the main pin 16 and the associated jaw set to theuniversal body 18. Specifically, the sides 19 include receiving members42 at the ends thereof which are adapted to be received in grooves inthe bridge housings 48 for attaching the universal body 18 to the bridgehousing 48. Keeper pins 50 are received through apertures 52 in thebridge housing 48 and the receiving members 42. Keeper screws or bolts54 can be used to secure each keeper pin 50 to one bridge housing 48. Inthis arrangement, the outer bearing structure surrounding the main pin16 will remain affixed even when the tool unit is removed from theuniversal body 18. This provides the advantage that all the bearing orrotating surfaces will be protected from dirt and grit even when thetool unit is disassembled. A modification of the quick connecting systemis shown in FIGS. 11 b-d. FIGS. 11 b and 11 c show a modified bridgehousing 48′ which receives keeper pins 50′ in apertures 52 in the bridgehousing 48′. The keeper pins 50′ are held in place by a keeper 54′ asshown in FIG. 11 c. Specifically, the shaft of the keeper 54′ isreceived in a locking groove 55 formed in the keeper pins 50′ as shownin FIG. 11 d. FIGS. 11 b-d illustrate that various modifications may bemade to the quick change system within the scope of the presentinvention. Each keeper 54′ is held in place by a retainer 55′, such as athreaded plug or the like.

The quick change design of the present invention allows the universalbody 18 to accommodate a wide variety of tool units. For example, theshear 10 formed by the first blade 12 and second blade 14 can bereplaced with a plate shear 100 illustrated in FIGS. 12 and 13 havingdistinct blades 102 and 104. The plate shear 100 is similar to shear 10except that the jaw of blades 102 and 104 is specifically designed forcutting plate. The plate shear 100 is similar to the shear 10 in that itis specifically designed for cutting metal products.

FIGS. 18 and 19 illustrate a wood shear 110 utilized with the universalbody 18 of the present invention. Wood shear 110 includes blades 112 and114 specifically designed for cutting wood products.

FIGS. 14 and 15 illustrate a concrete cracker 120 for use with theuniversal body 18. The concrete cracker 120 includes jaws 122 and 124designed specifically for cracking concrete structures. Each jaw 122 and124 includes concrete crushing inserts 126 at a distal end thereofcooperating with the crushing insert 126 on an opposite jaw 122 or 124as well as cutting inserts 70 adjacent the main pin 16 which provide ashearing relationship with the cutting inserts 70 of the associated jaw122 or 124.

FIGS. 16 and 17 illustrate a concrete pulverizer 130 for use with theuniversal body 18 of the present invention. The concrete pulverizer 130includes jaws 132 and 134 associated with crushing of concrete. The jaws132 and 134 include crushing inserts 126 cooperating with inserts 126 onan opposite jaw 132 and 134.

FIGS. 20 and 21 illustrate a grapple 140 for use with the universal body18 of the present invention. The grapple 140 includes jaws 142 and 144having hook-shaped tines 146 extending from each jaw 142 and 144. Thetines 146 of each jaw 142 and 144 are designed to extend between spacesof the tines 146 on the opposed jaw 142 or 144 such that the tines 146can overlap in a closed position to completely encircle the work piece.

FIGS. 22 and 23 illustrate an iron and rail cracker 150 for use with theuniversal body 18 of the present invention. The iron and rail cracker150 includes jaws 152 and 154 having interposed inserts 156 thereon. Theiron and rail cracker 150 is designed to crack rail and cast ironproducts, such as engine blocks and the like.

The series of tools illustrated in the figures is merely intended to berepresentative of the tools which can be designed for use with theuniversal body 18. The quick disconnect feature provided by the bridgehousing 48 on each tool facilitates the rapid tool change of the presentinvention. It will be appreciated that the linkages 24 and 28 must alsobe disconnected during the change. This is easily accomplished throughremoval of the respective pivot pins 26 and 30. Consequently thelinkages 24 and 28 can be considered part of the universal body 18 sincethese are likely to be common to multiple tool sets. It is also possibleto change out the linkages with the tool sets by either disconnectingthe linkages 24 and 28 from the slide member 32 or disconnecting theslide member 32 from the hydraulic cylinder 38. This may be desiredwhere a tool set requires a change in the linkage lengths. Differenttools may have different respective linkage lengths.

Due to the rotation of the forward portions of the universal body 18through the rotary coupling 23, the rotation must be addressed in thehydraulic cylinder 38 and the hydraulic lines leading thereto. Thehydraulic cylinder 38 is provided as a combined hydraulic cylinder androtary joint to accommodate the provision of the rotary coupling 23. Asshown in FIGS. 24 and 25, the hydraulic cylinder 38 includes a cylinderhousing 160 which is rotatable with the universal body 18 through thetrunnion 40. The cylinder housing 160 includes a cylinder extension 162attached thereto which includes hydraulic lines 164 and 166appropriately coupled for driving opposite ends of a piston 168 withinthe cylinder housing 160. The piston rod 36 is attached to the piston168. The cylinder extension 162 is received within a stationary housing170 which is secured to the bearing housing 20. The stationary housing170 includes hydraulic ports 172 and 174 communicating with respectivehydraulic lines 164 and 166. As illustrated in FIG. 25, the hydraulicports 172 and 174 are channels around the interior of stationary housing170 which provides constant fluid communication between the hydraulicports 172 and 174 and the associated hydraulic lines 164 and 166throughout rotation of the cylinder extension 162 relative to thestationary housing 170. Hydraulic lines 176 and 178 extend from the endsof hydraulic lines 164 and 166 to the appropriate interior portions ofthe cylinder housing 160 as shown in FIG. 25. This design of thehydraulic cylinder 38 accommodates the provision of a rotary coupling 23without the need for a separate rotary joint. This design also providesa far more compact arrangement for the universal body 18 than if aseparate rotary joint were utilized.

FIG. 26 illustrates the geometric relationships of the shear 10according to the present invention. As illustrated in FIG. 26, therelevant parameters for the shear 10 include the lengths of each linkage24 and 28 and lever arms 180 and 182 of the first blade 12 and secondblade 14, respectively. The lever arms 180 and 182 for each blade 12 and14 is the distance between the respective pivot pins 26 and 30 and themain pin 16. Further parameters include the jaw depth defined as thedistance between the tip of the jaw and the innermost usable portion ofthat jaw and the maximum shear opening between the respective ends ofthe first blade 12 and second blade 14 as illustrated in FIG. 26. Theshear 10 of the present invention optimizes the operationalcharacteristics by analyzing and setting these dimensions to properlyposition the associated power curve. For example, in one embodiment, thepower curve shown in FIG. 27 a is set to continuously increasethroughout the jaw movement by providing the shear opening, the shearjaw depth, the knife lever arm and links having substantially the samedimensional lengths. Maintaining these elements as substantially equalmay help maximize the jaw opening as well as jaw depth and availableshear tonnage. The present invention provides for the shaping andregulation of the power curve by selecting the relative dimensionsaccordingly. For example, FIG. 27 b shows the power curve for oneembodiment of the present invention in which the dimensions are selectedso that the power curve peaks near the end of the cutting motion.

The cutting effort for each blade 12 or 14 as a function of the linkagegeometry utilized in the shear 10 is calculated according to thefollowing equation:Cutting Effort=(Lever Arm)×(Cylinder Force/2)×sin(β)/cos(θ); wherein 62is the angle between the lever arm 180 and 182 and the associatedlinkage 24 or 28 and θ is the angle between the longitudinal axis of thecylinder 38 and the respective linkage 24 or 28.

The cutting force produced by the shear 10 at any location along theshear cutting edge can be calculated by dividing the cutting effort bythe distance measured from the main pin 16 to the desired location alongthe blade 12 or 14. In order to optimize the geometric parameters of theshear 10 according to the present invention, the above parameters werevaried and the resulting cutting torques where studied. The cuttingtorque is defined as the torque applied to the respective blade 12 or 14about the main pin 16 by the hydraulic cylinder 38 through the pistonrod 36, slide member 32 and associated linkage 24 or 28. This torque canbe converted to a single force along the blade 12 or 14 by dividing thetorque by the distance from the center of the main pin 16 to the desiredlocation on the blade 12 or 14. The numerical value of the cuttingtorque is at its minimum when the blades 12 and 14 are fully open. Thetorque continuously increases in value as the blades 12 or 14 move tothe fully closed position. FIG. 27 a illustrates the favorable cuttingforce or power curve achieved with one shear of the present invention.FIG. 27 a illustrates the force generated at the throat and piercing tipfor the shear 10 through the various jaw positions which is shown in thelower portion of the graph. It is of particular importance to note thatthe power curve of this shear continually increases throughout the jawclosing cycle. The jaw position is graphed as the distance between thepiercing tip and the lower jaw with the negative values reflecting whenthe portions of the upper jaw are moving through a slot in the lowerjaw. The relative dimensions of the jaw parameters can be selected tovary the power curve as desired. For example, it may be advantageous tohave the power curve peak slightly before the end of the jaw cycle whenthe maximum cutting forces are needed such as shown in FIG. 27 b.Providing the linkage lengths slightly greater than the lever arms maybe used to achieve this design.

A review of the effect of changing the relevant parameters will clarifythe advantages of the design of the shear 10 of the present invention aswell as the tool design method of the present invention. Increasing thelength of the lever arm 180 or 182 of the respective blade 12 or 14results in the increased values of cutting torque for all positions ofthe blade 12 or 14 from fully open to fully closed. However, the lengthof the respective lever arm 180 and 182 is, of course, limited by thedesired overall dimensions of the shear 10. Varying the length of thelinkages 24 and 28 has various effects on the cutting torque. If thelinkages 24 and 28 are longer than the respective lever arms 180 and182, the cutting torque curve versus the blade 12 and 14 position willincrease in value until reaching a peak and then decreasing until theblades 12 and 14 are closed. One embodiment of the present inventionutilizes this concept to position the maximum cutting torque near theend of the jaw moving cycle. If the length of the linkages 24 and 28 isshorter than the respective lever arms 180 and 182, the torque valuewill continuously increase from the open to the closed position. As thelength of the linkage arms 24 and 28 increases, the value of the cuttingtorque at the open position increases and the value of the closedposition decreases. Having the linkages 24 and 28 substantially the samelength as the lever arms 180 and 182 results in one shear design whichconsiders all of the factors to be balanced.

The hydraulic cylinder 38 also has an effect on the power of theassociated shear 10. Increasing the diameter of the hydraulic cylinder38 results in an increased cutting torque for all the blade positions(12 and 14) and also increases the open/closed cycle time for the shear10. The size of the hydraulic cylinder 38 is effectively determined bythe size of the shear 10 and the operating conditions desired.

In addition to the lengths of the linkages 24 and 28 and the length ofthe respective lever arms 180 and 182, the value of the angles 0 betweenthe respective linkages 24 and 28 and the longitudinal axis of thehydraulic cylinder 38, and an angle (p between the lever arm 180 and 182and the longitudinal axis of the hydraulic cylinder 38 will depend onthe initial distance between the pivot pin 34 and the main pin 16 in thefully open position. To allow for the needed pin diameters, requiredbushings and the like, the initial values of these angles should be atleast 20 degrees. Due to the nature of the force transmission at pivotpin 34 and slide member 32, the final value of these angles will be lessthan 90 degrees and should be approximately 80 degrees.

The initial distance between pivot pin 34 and main pin 16 is limited bytwo physical limitations. First, the distance must be less than the sumof the lengths of the respective lever arm 180 and 182 and linkage 24 or28 by enough to allow the angles θ and φ discussed above to be at leastabout 20 degrees in the open position. Second, this distance must belarge enough so that the pivot pin 34 will not run into the main pin 16at the closed position. Decreasing the length of this initial distancedecreases the cutting torque at all positions.

Another issue to review is the total jaw rotation angle. Increasing thesize of the initial jaw opening increases the angular rotation necessaryto go from the open position to the closed position. However, increasingthis rotational angle also has an effect on the cutting torque curve.Increasing the total rotation angle causes an increase in the cuttingtorque when the jaws are almost fully open and a decrease in the cuttingtorque when in the fully closed position. Balancing all of the aboveconsiderations in the design of the shear 10 of FIG. 1 results in theshear opening, jaw depth, lever arm and linkage length being allsubstantially the same dimensional length. This ratio works for shearsof all sizes such that the specific value of this dimensional lengthwill depend upon the size of the shear desired. This relationshipbetween the linkage length and the lever arm may also be maintained forthe various tools illustrated in FIGS. 12-23. The other relationshipsmay be altered due to jaw structure changes.

Another important aspect of the present invention is the jaw structureof shear 10. The cutting edge of the first blade 12 is formed of aplurality of removable cutting inserts 190 removably attached to thefirst blade 12 by bolts or the like as well-known in the art. Theseinserts 190 may be indexible, meaning that the inserts 190 may beremoved and rotated to provide new cutting edges as one cutting edge isworn. The first blade 12 includes a piercing tip 192 at a distal end ofthe first blade 12. The piercing tip 192 is also a removable cuttinginsert. However, the piercing tip 192 is intended to primarily make acut transverse to the cut supplied by the cutting inserts 190.Specifically, the primary cut of the piercing tip 192 would be extendinginto and out of the illustration in FIG. 1. Additionally, the cuttinginserts 190 along the first blade 12 are positioned in a hook shape toprovide a first cutting portion 194 and a longer second cutting portion196 positioned between the first cutting position 194 and the piercingtip 192. The shear 10 is designed so that the first cutting portion 194is significantly less than, and preferably approximately one-half of,the length of the second cutting portion 196. The second blade 14includes a plurality of cutting inserts 190 which are positioned inshearing relation with the cutting inserts 190 and piercing tip 192 toprovide the shearing action for the shear 10. The second blade 14provides a slot for the first blade 12 to extend through during theshearing action with the slot helping to maintain the cutting inserts190 in shearing relation. The jaw design of the first blade 12 andsecond blade 14 in the shear 10 is constructed to help move material tobe severed to the throat area adjacent the main pin 16 where the cuttingforces are the highest. Having the piercing tip 192 sever the work piecein a direction transverse to the cutting of the first cutting portion194 and second cutting portion 196 will help draw the material back tothe throat. Additionally, the hook shape, i.e., the angle, between thefirst cutting portion 194 and the second cutting portion 196 will alsoserve to pull the material back to the throat area. Finally, theprovision of the first cutting portion 194 having a dimensionsignificantly less than the second cutting portion 196 will furtherassure that the material is pulled closer to the throat for cutting.This is believed to provide a significant improvement over the jawdesigns of existing shears with plural movable blades and complimentsthe power curve associated with the shear design to magnify theeffective shearing force. It is also within the scope of the presentinvention that different shapes for the piercing tip 192 may be utilizedfor different types of material. Specifically, a piercing tip having asharper or shallower angle when viewed from the side may be more or lessappropriate for distinct types of work pieces.

FIG. 5 additionally illustrates that the sides 19 of the universal body18 are pivoted to the yoke 21 through side pivots 78. This allows foreasy replacement of the first and second blades 12 and 14 with theassociated linkages 24 and 28, if desired. The pivotable sides 19 of theuniversal body 18 can be secured together by bolts or other fasteningmembers. A rectangular tie bar 79 is positioned between the pivotablesides 19 through which the securing bolts extend. The tie bar 79 helpsto maintain structural integrity of the universal body 18.

FIGS. 28-30 illustrate a shear 10 similar to shear 10 of FIG. 1, exceptthat the quick change feature is modified to utilize the pivoting sides19 of the universal body 18. Specifically, the bridge housing 48 hasbeen omitted and the main pin 16 is used to couple the jaw set directlyto the universal body 18. FIG. 29 illustrates bolts 198 which can beused for holding the sides 19 of the universal body 18 together.

FIGS. 31-34 schematically illustrate the process of disassembling thejaw structure and inserting a new jaw structure at the main pin 16 forthe quick change device shown in FIGS. 28-30. As best shown in thesefigures, this design essentially keeps the structure generallysymmetrical about the center line thereby avoiding inappropriatetorquing during use of the shear 10. It will be appreciated that bearingsleeves 202 may be positioned between appropriate elements and the mainpin 16. Retaining members 204 may be secured for holding the assembly inplace.

As illustrated in FIG. 32, by removing retaining bolts 206, a retainingcap 208, retaining clips 210 and an alignment sleeve 212 from attachmentwith the sides 19 of the universal body 18, the main pin 16 andassociated assembly is ready for removal. As shown in FIG. 33, once theretaining system has been disassembled, the sides 19 of the universalbody 18 rotate outwardly to simplify the removal process.

It will be apparent that before the first and second blades 12 and 14can be removed, the linkages 24 and 28 must be detached from either thefirst and second blades 12 and 14 or the slide member 32. In general,the pivot pins 26 and 30 are removed for disconnecting the linkages 24and 28 from the respective blades 12 and 14. However, it is possible forthe linkages 24 and 28 to remain with the blades 12 and 14 as a singletool unit. This may be important if different linkage lengths aredesired for the next tool set.

Maintaining the first linkage 24 and the second linkage 28 with thefirst and second blades 12 and 14 requires the decoupling of thelinkages 24 and 28 from the slide member 32, or alternatively,decoupling the slide member 32 from the piston rod 36. In this latterarrangement, the decoupling of the slide member 32 from the piston rod36 can be by bolts, a pin type connection or other secure fasteningwhich can be easily disassembled. A continuous sleeve 214, shown in FIG.6, is positioned around pivot pin 34 which couples the linkages 24 and28 to the slide member 32. The sleeve 214 provides that the linkages 24and 28 will be held together in a single assembly around sleeve 214following the removal of pivot pin 34. This structure allows thelinkages 24 and 28 to be removed, if needed. The removal of the linkagesmay be desired so that the linkage lengths can be changed with the nexttool set.

Regardless of how the linkages are decoupled, with the linkages 24 and28 decoupled and the sides 19 of the universal body 18 rotated outward,the entire jaw structure comprising the blades 12 and 14, and linkages24 and 28, if maintained with the blades 12 and 14, can be removed and aseparate tool assembly installed (with new linkages 24 and 28 if thesewere removed). Following this assembly, the sides of the universal body18 will be pivoted back together and the retaining system attachedaround a new main pin 16 such as shown in FIG. 32. Bolts will reattachthe sides 19 of the universal body 18 to complete the reassembly. Asshown in FIG. 34, the new blades 12 and 14 have different retainingmembers and bearing sleeves associated with this particular tool unit. Aparticular bearing structure will be designed in accordance with thespecific tool unit implemented.

FIG. 35 illustrates a shear 10 which incorporates a side access plate222 for permitting access to the slide member 32 and the associatedpivot pin 34. Specifically, the universal body 18 includes the accessplates 222 secured thereto which can be removed to gain access to theguided slide member 32 within the universal body 18.

FIG. 36 illustrates a modified universal body 18 in which the bolts forattaching the pivotable sides 19 of the universal body 18 are replacedwith a retaining connection 224.

FIGS. 37 and 38 illustrate a modified universal body 18 in which thesides 19 of the universal body 18 are pivoted about side pivots 78 andare secured by independent retaining connections 224 to the universalbody 18.

FIGS. 39 and 40 illustrate a further modified universal body 18 in whichthe sides 19 of the universal body 18 are completely separable from theremaining portions of the universal body 18 and secured thereto by theattachment of the trunnion 40 and separate retaining connections 224.

FIG. 41 illustrates a modification of the shear 10 in which the slot 44is replaced with a guide rod 230 upon which the slide member 32 slides.This modification also results in changing the attachment of thelinkages 24 and 28 from a common position to separate offset positionsby independent pins 232 and 234. This change also results in a change inthe geometric relationship discussed above in which the offset createdmust be accounted for in the resulting shear. This offset provides aless desirable shear in terms of cutting characteristics.

Another aspect of the present invention is the details of the slidemember 32 and the coupling to the piston rod 36 as shown in FIGS. 4, 6and 7. A sleeve 214 is specifically formed as a hardened steel memberand is keyed to the pivot pin 34 through a key 242 positioned behind acover plate 244. Wear plates 246 are on the sides of the slide member 32to be captured in the slot 44 against wear plates 248 in groove 44. Theslide member 32 is connected through a pin 250 to a rod eye 252 of thepiston rod 36. The pin 250 allows for rotation of the rod 36 about anaxis which is 90 degrees from the axis of the trunnion 40. The sleeve214 will maintain the linkages 24 and 28 together even following removalof the pin 34. Additionally, the replaceable sleeve 214 absorbs most ofthe transmitted shear load such that most of the wear will occur on thesleeve 214 and not the pin 34. Bushings 260 located at each linkage 24and 28 will ensure proper alignment and eliminate linkage-to-linkage, orlinkage-to-slide member, wear. Keying the pivot pin 34, sleeve 214 andslide member 32 together by key 242 will prevent rotation of the pin 34or sleeve 214 and eliminate the likelihood of flat spots developing oneither structure. The pinning of the rod eye 252 to the slide member 32allows for misalignment in relation to the hydraulic cylinder 38 and theslide member 32 which, in conjunction with the trunnion 40, will help toprolong the seal life of the hydraulic cylinder 38. Finally, it isanticipated that the wear plates 246 will be made of high wear brasswith impregnated graphite, thus eliminating the need for lubrication ofthese components. These components will serve two functions. First, theyprevent the frictional wear between the slide member 32 and the matingpart in the slot 44. Second, the wear plates 246 serve to keep exactlinear motion of the slide member 32 in the event of unperceived sideloading, thereby maintaining the highest possible cylinder force inoperation.

FIG. 42 is a schematic illustration of a jaw and linkage design alsoincluding an offset similar to that shown in FIG. 41. However, theembodiment illustrated in FIG. 42 is considered a “negative” offset dueto the crossing of the respective linkages 24 and 28. The negativeoffset represented by the embodiment illustrated in FIG. 42 may have abeneficial effect in the theoretical operation of the shear, however,appropriate design of the crossing or linkage arrangement increases thecomplexity of the device.

FIG. 43 illustrates an embodiment of the shear 10 in which a rotatableconnection 280 is provided between the piston rod 36 and the slidemember 32. The provision of the rotational coupling 280 means that thetrunnion 40 can be moved back and utilized for attaching the hydrauliccylinder 38 to the bearing housing 20 rather than attaching it to theyoke 21. Furthermore, since the hydraulic cylinder 38 will not rotatewhen the universal body 18 rotates, a simple, more conventionalhydraulic cylinder 38 can be utilized in this embodiment.

FIGS. 44-46 illustrate a shear 300 of a distinct type different from theshear 10. Specifically, the shear 300 includes a first pivotable blade302 pivotally attached to a fixed blade 304 through a hub 305. The shear300 is similar to the shear 10 in that a linkage 306 couples the blade302 to a slide member 308 which is received in a guiding slot 310. Theshear 300 additionally includes piston rod 36, hydraulic cylinder 38,trunnion 40 and the bearing housing 20 similar to shear 10 describedabove.

FIGS. 47 and 48 illustrate a modification of shear 300 in which theslide member 308 and slot 310 are replaced with a separate linkage 312to the fixed blade 304 and the rod eye 252 of piston rod 36. The linkage306 is also attached to the rod eye 252 and linkage 312. In thisembodiment, the guiding of the piston is non-linear and travels throughan arc defined by the linkage 312. The hydraulic cylinder 38 will alsopivot about trunnion 40 throughout the movement of the linkage 312.

FIGS. 49-53 illustrate a shear 10 which details a universal body 18incorporating a simple four pin connection between the rotary coupling23 and an adapter 20 a. The adapter 20 a essentially replaces thebearing housing 20 of earlier embodiments. As shown in FIGS. 50 and 51the rotary coupling 23 includes parallel connecting plates 320 whichreceive four connector pin assemblies 330. The connector pin assemblies330 provide a simple connection between the rotary coupling 23 and theadapter 20 a. A connector pin assembly 330 is shown in detail in FIG.51. Each connector pin assembly 330 includes a connecting pin 332received in and extending between a pair of adjacent connector plates320 within bushings 334 and 336. The bushing 336 and the connecting pin332 receive a locking bolt 338 secured by a nut 340 to hold theconnector pin assembly 330 in position. As shown in FIGS. 52 and 53, theadapter 20 a includes a pair of parallel side plates having receivingapertures 342 that are received between pairs of adjacent connectingplates 320 to receive the connecting pin 332 therethrough. This providesa simple, easily released connection between the rotary coupling 23 andthe adapter 20 a.

FIG. 54 illustrates a shear 10′ which details a universal body 18′incorporating a simple four pin connection between the yoke 21′ and theadapter 20 a. The four pin connection is similar to the shear of FIG. 49except without a rotary coupling in the universal body. The parallelconnecting plates extend from the yoke 21′ rather than the rotarycoupling.

FIG. 55 illustrates a shear 10 incorporating a simple four pinconnection between the rotary coupling 23 and the adapter 20 a as shownin FIG. 49. The shear 10 of FIG. 55 is designed as a stick mounted typeshear, also referred to as a third member mount type adapter.Essentially, the adapter 20 a is configured for this type ofarrangement. FIG. 55 further illustrates the versatility of the shearsof the present invention.

It will be apparent to those of ordinary skill in the art that variousmodifications may be made to the present invention without departingfrom the spirit and scope thereof. The described embodiments areintended merely to be illustrative of the concepts of the presentinvention and not restrictive thereof.

1. A method of designing and forming a demolition tool unit having apair of movable blades forming a jaw structure, a linkage connected toeach blade, and a common hydraulic cylinder attached to each linkage formoving the blades, the method comprising the steps of: A) developing ageneral jaw geometry which defines main geometric parameters of thegeneral jaw structure of the demolition tool unit; B) analyzing the jawgeometry to determine at least the working torque of general jawstructure throughout the range of motion of the blades; C) determiningthe relative value of main geometric parameters of the general jawstructure which at least optimizes the working torque characteristicsthroughout the range of motion of the blades; and D) forming ademolition tool unit having the main geometric parameters determined instep C).
 2. The method of claim 1 wherein the main geometric parametersof the general jaw structure which are analyzed include a lever arm ofeach blade and a length of each linkage.
 3. The method of claim 3wherein the main geometric parameters of the general jaw structure whichare analyzed further include a jaw depth of the blades, a maximumopening of the blades, a relative angular orientation of the linkages tothe hydraulic cylinder and a relative angular orientation of the leverarm to the hydraulic cylinder.
 4. The method of claim 3 furtherincluding the step of analyzing the cycle time of the general jawstructure.
 5. The method of claim 1 wherein the maximum working torqueis set near the closed position of the blades.
 6. The method of claim 1wherein the working torque increases throughout the blade movement. 7.The method of claim 1 wherein the step of determining the relative valueof main geometric parameters includes varying the lengths of thelinkages and of the lever arms.
 8. The method of claim 1 wherein thestep of determining the relative value of main geometric parametersincludes varying the distance between the end of each linkage and thecenter line of the hydraulic cylinder.